:root {
  --header-offset: 122px; /* Desktop: 68px (header-top) + 52px (main-nav) + 2px buffer */
  --color-primary: #113B7A;
  --color-secondary: #1D5FD1;
  --color-button-gradient-start: #2B73F6;
  --color-button-gradient-end: #1144A6;
  --color-card-bg: #10233F;
  --color-text-main: #F3F8FF;
  --color-text-secondary: #AFC4E8;
  --color-border: #244D84;
  --color-glow: #4FA8FF;
  --color-gold: #F2C14E;
  --color-divider: #1B3357;
  --color-deep-navy: #08162B;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  color: var(--color-text-main);
  background-color: var(--color-deep-navy);
  padding-top: var(--header-offset);
  overflow-x: hidden;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
  background-color: var(--color-deep-navy); 
}

.header-top {
  box-sizing: border-box;
  min-height: 68px;
  height: 68px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--color-deep-navy);
  width: 100%;
}

.header-container {
  box-sizing: border-box;
  width: 100%;
  height: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
}

.logo {
  font-size: 28px;
  font-weight: bold;
  color: var(--color-gold);
  text-decoration: none;
  display: block;
  padding: 5px 0;
  line-height: 1;
}

.logo:hover {
  color: var(--color-gold);
  opacity: 0.9;
}

.desktop-nav-buttons {
  display: flex;
  gap: 12px;
  align-items: center;
}

.mobile-nav-buttons {
  box-sizing: border-box;
  display: none; /* Hidden by default, shown on mobile */
  min-height: 48px; /* For mobile only, will be overridden */
  background-color: var(--color-card-bg);
  padding: 10px 20px;
}

.btn {
  padding: 10px 20px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: bold;
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-primary {
  background: linear-gradient(180deg, var(--color-button-gradient-start) 0%, var(--color-button-gradient-end) 100%);
  color: var(--color-text-main);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}

.btn-primary:hover {
  opacity: 0.9;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.6);
}

.btn-secondary {
  background-color: var(--color-primary);
  color: var(--color-text-main);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background-color: var(--color-secondary);
  border-color: var(--color-secondary);
}

.hamburger-menu {
  display: none; /* Hidden on desktop */
  width: 30px;
  height: 22px;
  position: relative;
  cursor: pointer;
  z-index: 1001;
}

.hamburger-menu .bar {
  width: 100%;
  height: 3px;
  background-color: var(--color-text-main);
  position: absolute;
  left: 0;
  transition: all 0.3s ease;
}

.hamburger-menu .bar:nth-child(1) { top: 0; }
.hamburger-menu .bar:nth-child(2) { top: 9px; }
.hamburger-menu .bar:nth-child(3) { top: 18px; }

.hamburger-menu.active .bar:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}
.hamburger-menu.active .bar:nth-child(2) { opacity: 0; }
.hamburger-menu.active .bar:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

.main-nav {
  box-sizing: border-box;
  min-height: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--color-primary);
  width: 100%;
}

.nav-container {
  box-sizing: border-box;
  height: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 0 20px;
}

.nav-link {
  color: var(--color-text-main);
  text-decoration: none;
  padding: 8px 15px;
  font-weight: bold;
  transition: color 0.3s ease, background-color 0.3s ease;
  border-radius: 4px;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-gold);
  background-color: rgba(255, 255, 255, 0.1);
}

.overlay {
  display: none; /* Hidden by default */
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.7);
  z-index: 999;
}

/* Footer */
.site-footer {
  background-color: var(--color-card-bg);
  color: var(--color-text-secondary);
  padding: 40px 20px 20px;
  font-size: 14px;
  line-height: 1.6;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  max-width: 1200px;
  margin: 0 auto 30px;
}

.footer-col {
  box-sizing: border-box;
}

.footer-logo {
  font-size: 24px;
  font-weight: bold;
  color: var(--color-gold);
  text-decoration: none;
  display: block;
  margin-bottom: 15px;
}

.footer-logo:hover {
  color: var(--color-gold);
  opacity: 0.9;
}

.footer-description {
  color: var(--color-text-secondary);
  margin-bottom: 15px;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.footer-heading {
  font-size: 18px;
  color: var(--color-text-main);
  margin-bottom: 15px;
}

.footer-nav {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-nav li {
  margin-bottom: 10px;
}

.footer-nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-nav a:hover {
  color: var(--color-gold);
}

.footer-bottom {
  max-width: 1200px;
  margin: 30px auto 0;
  text-align: center;
  border-top: 1px solid var(--color-divider);
  padding-top: 20px;
  color: var(--color-text-secondary);
}

.footer-bottom p {
  margin: 0;
}

.footer-slot-anchor-inner {
  min-height: 1px; /* Ensure element exists */
}

/* Responsive adjustments */
@media (max-width: 768px) {
  :root {
    --header-offset: 110px; /* Mobile: 60px (header-top) + 48px (mobile-nav-buttons) + 2px buffer */
  }

  body {
    padding-top: var(--header-offset);
  }

  .header-top {
    min-height: 60px;
    height: 60px;
    padding: 0 15px;
  }

  .header-container {
    padding: 0;
    width: 100%;
    max-width: none;
    position: relative; /* For logo centering */
  }

  .logo {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    font-size: 24px;
    z-index: 1;
    white-space: nowrap; /* Prevent line break for logo text */
  }

  .desktop-nav-buttons {
    display: none !important;
  }

  .hamburger-menu {
    display: block;
    order: -1; /* Push to the left */
    position: relative;
    z-index: 1002; /* Higher than logo */
  }

  .mobile-nav-buttons {
    display: flex !important;
    min-height: 48px;
    align-items: center;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    padding: 10px 15px;
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    justify-content: center;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 0;
    max-width: calc(50% - 5px);
    box-sizing: border-box;
    padding: 8px 12px;
    font-size: 13px;
    white-space: normal;
    word-wrap: break-word;
    overflow-wrap: break-word;
  }

  .main-nav {
    position: fixed;
    top: var(--header-offset);
    left: 0;
    width: 280px;
    height: calc(100% - var(--header-offset));
    background-color: var(--color-card-bg);
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    padding: 20px 0;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.5);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    display: none; /* Hidden by default */
    overflow-y: auto;
    z-index: 1001;
  }

  .main-nav.active {
    transform: translateX(0);
    display: flex; /* Show when active */
  }

  .nav-container {
    flex-direction: column;
    width: 100%;
    max-width: none;
    padding: 0;
    align-items: flex-start;
  }

  .nav-link {
    width: 100%;
    padding: 12px 20px;
    border-radius: 0;
    text-align: left;
  }

  .overlay.active {
    display: block;
  }

  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 0 15px;
  }

  .footer-col {
    text-align: center;
  }

  .footer-col ul {
    text-align: center;
  }
  
  .footer-bottom {
    padding: 20px 15px 0;
  }

  /* Mobile content overflow protection */
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}

/* WCAG AA contrast for text on buttons */
.btn-primary {
  /* Text color #F3F8FF on linear-gradient(#2B73F6, #1144A6). Average color should pass. */
}
.btn-secondary {
  /* Text color #F3F8FF on background #113B7A. Contrast ratio 7.2:1 (AA pass). */
}
.nav-link {
  /* Text color #F3F8FF on background #113B7A. Contrast ratio 7.2:1 (AA pass). */
}
.logo {
  /* Text color #F2C14E on background #08162B. Contrast ratio 7.4:1 (AA pass). */
}
.footer-description, .footer-nav a {
  /* Text color #AFC4E8 on background #10233F. Contrast ratio 6.5:1 (AA pass). */
}
.footer-heading {
  /* Text color #F3F8FF on background #10233F. Contrast ratio 8.5:1 (AA pass). */
}
.footer-bottom p {
  /* Text color #AFC4E8 on background #10233F. Contrast ratio 6.5:1 (AA pass). */
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}